The following are just a few observations about the way mics are used for live television etc and gives viewers the impression of less ambient sound in some cases and that the people screaming into them are a bit crazy. Regardless of what you think about these people the way you perceive their interviews or sound bites taken from a football, a live rally or just street footage has more to do with the technology used to get clear sound and filter out unwanted background noise then with excesses on their parts. If a person is screaming because they can't hear themselves over a noisy crowd but you only get to hear their voice, then yeah, you might think they're a bit nutty.
Anyway, as a musician there are many times I've gotten off a stage hoarse from screaming into a mic because I didn't have good monitoring and couldn't hear myself sing over a noisy bar or crowd.
Things that happen when you scream into a Mic
The Richard Sherman post game interview after the Seahaw…
I've played Dark Side of the Moon twice today. Wish You Were Here once and am currently listening to Animals ( via youtube ). I own the remastered edition of TDSOTM and The Final Cut ( it's one of my favorite albums of all time in general. I know it's not exactly beloved by PF fans)